Insect Bites: The Sunday Digest – Cheating the super-organism

A familiar sight for many people, whether they are entomologically inclined or not, is ants working in what appears to be a cohesive manner. Naturalists in the early twentieth century described these assemblies of individual ants as ‘super-organisms’.

Like bees, wasps and termites, ants are eusocial. This means within one species there are often workers, soldiers and queens. Each of these so called castes has its own unique role within the colony and appear very different to each other despite being the same species. Individuals in these complex societies would be unable to survive alone; colony life is essential for individual survival.

Despite ants being evolutionarily and behaviourally advanced when compared to many other organisms, one group of beetles have managed to exploit them in an incredible way.  This group of beetles are a sub-family of rove beetles called Pselaphinae, pronounced “Seh-LAH-Fin-Ee”. This sub-family contains around 10,000 described species with many still undiscovered in ecosystems all over the world, and many left in museum collections still un-named. They have evolved complex morphological (structural) features which mean they can co-exist with ants, utilise colony resources and benefit from the ants’ protection.

Within Pselaphinae, a group of 369 species collectively known as the Clavigeritae (“Cla-Ve-JEH-Ri-Tee”) have taken the cheating to a whole new level. They have managed to fool ants into trophallaxis, a phenomenon where the ants directly feed the beetles, mouth-to-mouth. This kind of behaviour makes it clear that Pselaphinae seem to be treated as just another ant in the colony, evading the usual aggressive behaviour that ants exhibit towards outsiders! To facilitate this mouth-to-mouth feeding, the Clavigeritae have evolved brush like features (Trichomes) on the base of the abdomen which exude a substance that the worker ants find attractive to feed on, and seems to calm any aggressive behaviour. In addition, the beetles’ mandibles are not designed for hunting or grabbing prey, but perfectly suited to direct feeding from ants, being non-serrated and often circular in shape.

The development of these close and complex relationships between ants and Pselaphinae must surely be the result of million years of co-evolution. With ants containing a similar number of species to Pselaphinae, this may go some way in explaining the incredible diversity of these ant-exploiting beetles as they have specialised and speciated (the formation of new species) in close accordance with ant diversification.

A recent paper, published in “Current Biology” by Joseph Parker and David Grimaldi, has shed light on when these advanced ant-loving beetles first evolved and backs up the idea that Pselaphinae and ants have co-evolved for tens of millions of years. A single ant-loving beetle found in Indian Cambay amber that is about 52 million years old shows that these ant-loving beetles were present before ants diversified and gained dominance in ecosystems.

The association between ants and the organisms that ‘love’ them is known as myrmecophily. Other than numerous myrmecophilous species of Pselaphinae, these interactions are also found in another sub-family of rove beetles, Aleocharinae. This sub-family is even more diverse than Pselaphinae, containing 13,000 or so described species. Some myrmecophilous species of Aleocharinae resemble ants with constricted waists and a tendency to walk among the long winding trails of ant workers where they blend in perfectly. They themselves do not produce a chemical that appeases the ants, as in Pselaphinae, but instead they groom and obtain odours directly from them, thus enabling them to co-exist with the ants and perhaps, more importantly, avoid predators.

The Aleocharinae species Thyreoxenus brevitibialis has integrated into termite colonies by evolving a body form extremely similar to that of termites. The most obvious feature this beetle has evolved is the swelling of the abdomen, also known as physogastry, a typical characteristic seen in its victim.

The clown and king of termitophily is without a doubt Coatonachthodes ovambolandicus. Physogastry (swelling of the abdomen) in this species enables it to mimic its host termites down to a tee. The illustration below does the talking, showing all legs and antennae replicated in the beetles abdomen.

 

Capture

Coatonachthodes ovambolandicus: the termite mimic. Side on illustration (left) and dorsal view (right). Dorsal view showing the physogastric abdomen from above with all appendages including antennae mimicking a termite worker. Illustration from Kistner (1968), adapted by Kleisner & Markoš (2005).

It seems social insects are a victim of their own success, and not by coincidence. It is said that ant biomass is similar to that of humans and their impact on the environment is significant due to hoarding of materials for nests. The same can be said of termites and their mounds. These resource rich locations are clearly attractive to other organisms. In particular, Pselaphinae and Aleocharinae rove beetles have managed to exploit these advanced social insects perfectly, evolving to cheat the super-organism.

 

Author – Joshua Jenkins Shaw (@jenksshaw)

Further reading

Kistner, D.H. 1968. Revision of the African species of the termitophilous tribe Corotocini (Coeloptera: Stapylinidae). I. A new genus and species from Ovamboland and its zoogeographic significance. Journal of the New York Entomological Society 76. P213–221.

Kleisner, K. & Markoš, A. 2005. Semetic rings: towards the new concept of mimetic resemblances. Theory in Biosciences 123. P203-222.

Parker, J. & Grimaldi, D.A. 2014. Specialized myrmecophily at the ecological dawn of modern ants. Current Biology 24. P1-7.

Wheeler, W.M. 1911. The ant colony as an organism. Journal of Morphology 22. P307-325.

 

EntoMasters on Tour – The Royal Entomological Society

Monday the 3rd of November saw the Harper Adams Entomology and IPM students make their way down to The Mansion House situated outside of historic St. Albans for a visit to the hub of Entomology in the UK – The Royal Entomological Society. Coming in from the drizzly November morning we were met with tea, coffee, an array of delicious biscuity treats and friendly faces, much needed after being stuck in M1 traffic for a number of hours.

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Refreshing English Drizzle

Founded in 1833 and granted its royal charter by Queen Victoria in 1885, the principal aim of the society is ‘to promote the dissemination of knowledge in all fields of insect science and to improve communication between entomologists ’. The society, once situated in 41 Queens Gate, London, moved out of the capital in 2008 to the fantastic premises they inhabit in St. Albans today which has enabled a greater amount of funding to be allocated to research, journals and a number of awards for recognising achievement. Many fellows of the society are well renowned and famously include Charles Darwin, Alfred Russell Wallace and Harpers own Professor Simon Leather (Signatures can be found in the obligations book – here is Darwin’s! https://twitter.com/EntoProf/status/529359332157448192/photo/1).

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A Strepsiptera – Twisted Wing Parasite

After dosing up on hot drinks and biscuits we were shown into a small lecture room and listened to talks provided by members of the society. First up was Society’s Director of Science, Professor Jim Hardie, who welcomed us and gave us an insight into the history of the society including what insect is on the logo.

The floor was then handed over to Dr Luke Tilley, director of Outreach and coordinator of National Insect Week, who reinforced the importance of communication and enthusiasm about insects to the wider population and the need to inspire the next generation of potential entomologists. National Insect Week, organised by the Royal Entomological Society, brings together partners and multitude of hardworking volunteers who all share a keen interest in the science, history and conservation of insects to pass on their knowledge to the public and happens every two years across the United Kingdom (For more information on insects and how to get involved in National Insect Week 2016 visit http://www.nationalinsectweek.co.uk/).

As a short interactive exercise for practicing these communications skills we split into small groups and composed short fact files on various insects and tweets on a couple of journal articles. These needed to be eye-catching, interesting and be understandable from the viewpoint of someone who does not necessarily have a scientific background. Even though it was only a bit of fun it got the creative juices flowing and certainly made us think outside of the box.

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Kelleigh and Aidan enjoying the spread

Following this we had a delicious buffet lunch (The miniature yorkshire puddings being my personal favourite) along with a cheeky glass of wine and were given the opportunity to explore the society building. One thing that is noticeable when you first walk in is the fantastic collection of books that is spread throughout the ground floor. These all centre around the Royal Entomological Society library which holds very well preserved, rare books some pre-dating 1850 and all managed by the society’s librarian Val McAtear who bought out some examples and was incredibly trusting enough to let the Harper Students handle and look through them!

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Hundreds of years old and still extraordinarily vibrant

After perusing the RES merchandise and purchasing everything from books to umbrellas it was finally time to brave the M1 and head back up to Shropshire. On behalf of the Harper Adams Entomology and IPM masters I would like to thank the Royal Entomological Society for their hospitality and a great day out.

Richard Prew

Sources and further info:

 

The Curious Collections #1

This year’s cohort of MSc Entomology and IPM students have been given the opportunity to assist with the cataloguing and maintenance of the insect specimen collections here at Harper Adams University. A small team of us have started the task and oh boy what a task it is!

Like a sunken treasure chest, nobody really knew what to expect while we opened box after box after box. Some were full of outstanding specimens, ready to be used for education and research projects. Others were either empty or in serious disrepair.

The lack of a specimen catalogue in the Harper Adams collections stems from its brief but exciting history. The collections were saved from a handful of other institutions and transported from around the United Kingdom to a room in rural Shropshire. In this jumble of cabinets, drawers and boxes we have specimens from all over the world, some as old as 1897 and even some strange discoveries (such as the Golden Beetle pictured below, now named Beetleus spraypainta from a student project in 2011).

Bling Beetle

Spray painting is certainly an interesting if unorthodox way to jazz up a collection (however not recommended)

We inherited the task from Ceri Watkins who had soldiered on alone last year and made a fantastic start to the cataloguing project and got many specimens down to species level. This year’s collection team comprises of Dave Stanford-Beale, Richard Prew, Chris Mackin, Kelleigh Greene and Aidan Thomas who are squeezing in as much time as possible before the busy months ahead filled with research projects and more lectures.

Many of you readers may have already seen @coleopterist, Max Barclay’s blog on the importance of specimens and collections, where he stated:

“If a picture is worth a thousand words, the opportunity to handle a specimen may be worth a thousand pictures: nothing else can communicate the same sense of scale or detail. I know from daily experience the power of natural history collections to inspire awe and fascination”.

This team certainly agrees and we have learnt more about taxonomy and identification while going through these collections than we could have from simply reading a book or examining photographs. We are very honoured by having this opportunity and look forward to the Entohub and Harper Adams University Collections being able to be used by the entire HAU community easily and quickly to contribute to research.

We will post periodically throughout the year about progress in the collections and events. Keep updated by following this blog and our twitter page @entomasters

Collection Happiness

Chris bemused and Rich excitable over a fantastic box of Phasmids and Mantids

Written by Dave Stanford-Beale

 

 

New Arrivals

The new academic term has begun and with it the arrival of this year’s Entomology and Integrated Pest Management students.

We are a diverse bunch of individuals coming from all walks of life to study at Harper and bring with us a range of passions and interests which will be shared here along with events throughout the academic year.

Watch this space for all your Ento needs and also check out the EntoMasters Twitter feed at https://twitter.com/EntoMasters.

 

Admiring the Rothamsted Suction Trap at Warwick Crops

Admiring the Rothamsted Suction Trap at Warwick Crops